How To Guide [GUIDE] Pixel 5a "barbet": Unlock Bootloader, Update, Root, Pass SafetyNet

[cr1_1]

Hi,
Please reconsider the "deprecated" instructions about vbmeta :

fastboot flash vbmeta --disable-verity --disable-verification vbmeta.img

The above command SAVED me.

I was stuck in a slow motion bootloop (Pixel 5A and 4A both had this behavior) when upgrading from Android 11 to Android 12 on rooted phones with Magisk (both stable and canary versions). Even clean installs with factory reset did not stop this bootloop.

What finally did was doing a factory wipe, clean install using full factory images then rebooting into recovery (before booting into system) and selecting restart bootloader. From the bootloader (and from a PC) I used

fastboot flash vbmeta --disable-verity --disable-verification vbmeta.img

then rebooted into system. Rock solid stable.

So Magisk canary evidently doesn't do anything to the vbmeta flags. I still needed to explicitly disable the verfication settings.

Then I happily installed Magisk canary, configured the Zygist/Denylist, systemless hosts, and safety-net-fix 2.2.1.
All good, all stable.

 

[cr1_1]

Hi,
Please reconsider the "deprecated" instructions about vbmeta :

fastboot flash vbmeta --disable-verity --disable-verification vbmeta.img

The above command SAVED me.

I was stuck in a slow motion bootloop (Pixel 5A and 4A both had this behavior) when upgrading from Android 11 to Android 12 on rooted phones with Magisk (both stable and canary versions). Even clean installs with factory reset did not stop this bootloop.

What finally did was doing a factory wipe, clean install using full factory images then rebooting into recovery (before booting into system) and selecting restart bootloader. From the bootloader (and from a PC) I used

fastboot flash vbmeta --disable-verity --disable-verification vbmeta.img

then rebooted into system. Rock solid stable.

So Magisk canary evidently doesn't do anything to the vbmeta flags. I still needed to explicitly disable the verfication settings.

Then I happily installed Magisk canary, configured the Zygist/Denylist, systemless hosts, and safety-net-fix 2.2.1.
All good, all stable.

Nuts. after about 2 hours, the bootloop is back, after I rebooted manually. Does vbmeta get reset on reboot?

 

[V0latyle]

Nuts. after about 2 hours, the bootloop is back, after I rebooted manually. Does vbmeta get reset on reboot?

No, and you shouldn't have needed to disable verity or verification. Magisk does not change these flags; what WAS fixed was the way Magisk handles the boot image header, so it preserves the vbmeta flags within the boot image so that disabling verity/verification are not necessary. This was implemented in Canary 23016, which at the time I write this is still the current canary.

What version of Magisk are you using?

 

[cr1_1]

No, and you shouldn't have needed to disable verity or verification. Magisk does not change these flags; what WAS fixed was the way Magisk handles the boot image header, so it preserves the vbmeta flags within the boot image so that disabling verity/verification are not necessary. This was implemented in Canary 23016, which at the time I write this is still the current canary.

What version of Magisk are you using?

Hi, thank you for responding. I am using Canary 23016. Enabled Zygist, configure the Denylist to hide Google Play services, Google Play store, my banking app and GPay. Also installed safety-net-fix 2.2.0 and systemless hosts.

The looping began after flashing the magisk-patched boot image (taken from the Dec 5, 2021 barbet full factory boot.img. Upon rebooting into system, the looping began.

I also did a factory reset, without restoring any of my apps, just as when the Pixel5a came out of the box. When I installed Canary 23016 and then flashed the magisk-patched boot img, the same bootloop behavior appeared.

Since then I did a complete factory reset, restored my apps, etc. But did not install anything Magisk and obiously no root. The phone is now stable. no bootloop.

By the way, what I am calling a bootloop means booting up into the system, logging in, and waiting between 10 and 60 secs. the phone then freezes, becoming unresponsive to any touch, and the clock time freezes. Within another 30 secs after this freeze, the phone will reboot itself without my doing anything. Even if I then do not login but just leave the phone at the login screen, the freezing and eventual rebooting will continue.

Also, this rebooting is strange in that the unlocked bootloader warning screen does not appear so maybe it's some kind of partial reboot?

Anyway, much thanks for any suggestions you might have.

p.s. I can flash the Pixel5a with Android 11 os from Oct 2021, and root with Magisk stable, Riru, etc and the phone is rock solid. Also, this behavior is identical to a Pixel 4a I have when I tried upgrading to Android 12 on that phone.
Something in the magisk-patched boot.img is making both phones unstable. or maybe flashing any boot.img patched or not causes the instability?

 

[V0latyle]

Hi, thank you for responding. I am using Canary 23016. Enabled Zygist, configure the Denylist to hide Google Play services, Google Play store, my banking app and GPay. Also installed safety-net-fix 2.2.0 and systemless hosts.

The looping began after flashing the magisk-patched boot image (taken from the Dec 5, 2021 barbet full factory boot.img. Upon rebooting into system, the looping began.

I also did a factory reset, without restoring any of my apps, just as when the Pixel5a came out of the box. When I installed Canary 23016 and then flashed the magisk-patched boot img, the same bootloop behavior appeared.

Since then I did a complete factory reset, restored my apps, etc. But did not install anything Magisk and obiously no root. The phone is now stable. no bootloop.

By the way, what I am calling a bootloop means booting up into the system, logging in, and waiting between 10 and 60 secs. the phone then freezes, becoming unresponsive to any touch, and the clock time freezes. Within another 30 secs after this freeze, the phone will reboot itself without my doing anything. Even if I then do not login but just leave the phone at the login screen, the freezing and eventual rebooting will continue.

Also, this rebooting is strange in that the unlocked bootloader warning screen does not appear so maybe it's some kind of partial reboot?

Anyway, much thanks for any suggestions you might have.

p.s. I can flash the Pixel5a with Android 11 os from Oct 2021, and root with Magisk stable, Riru, etc and the phone is rock solid. Also, this behavior is identical to a Pixel 4a I have when I tried upgrading to Android 12 on that phone.
Something in the magisk-patched boot.img is making both phones unstable. or maybe flashing any boot.img patched or not causes the instability?

A properly patched boot image won't cause instability. You're having a unique issue.

Are you using the latest platform tools? Current version is 31.0.3

Can you try using another cable or PC?

Where did you download Magisk from?

 

[cr1_1]

A properly patched boot image won't cause instability. You're having a unique issue.

Are you using the latest platform tools? Current version is 31.0.3

Can you try using another cable or PC?

Where did you download Magisk from?

hi,
I checked and made sure I am using platform-tools_r31.0.3-windows as linked from Google's latest factory image page. I downloaded Canary from TopJohnWu's GitHub page. Also tried several new USB cables.

I tried doing yet another factory reset, and clean install using flash-all.bat with wipe. I set up the phone without restoring any of my apps, just the few default included Google apps. Downloaded Canary again.

Just for grins, I extracted boot.img from the Android 12 OS Dec 5, 2021 release, which is the factory image I have been using, rebooted into the bootloader and fastboot flash boot boot.img to see if flashing was somehow corrupting the boot.img. Rebooted into system and it is rock solid.
The same problem of bootlooping after flashing magisk-patched image occurred with the Nov 2021 Android 12 factory image.

Then I flashed the magisk-patched boot image. Rebooted into system. The phone was stable for several minutes.
I then rebooted the phone. And the bootlooping started up again. Why does rebooting triggered the bootloop instability?

I downloaded and partially installed Canary 23016 (didn't flash the boot image, just installed app-debug.apk.) And no problems . It is the flashing of the patched boot image which somehow causes the bootlooping

Nothing like this happened with Magisk and Android 11. rock solid. Sigh.

Thank you for your suggestions. Hopefully this can be solved. And the problem appears on Pixel4A and Pixel 5A.

 

[manjaroid]

Also, this rebooting is strange in that the unlocked bootloader warning screen does not appear so maybe it's some kind of partial reboot?

If you boot to the bootloader screen does it say it's unlocked?

 

[iamnitsuji]

Give V0latyle a standing ovation! These are the clearest root instructions I've ever followed. My last, older phone was fine with stable Magisk and no modules for passing SafetyNet. I am so glad I didn't try stable Magisk. I had no idea about Canary, Zygisk, and these modules. This was a piece of cake. Every app that cares, doesn't see that I'm rooted. Woo hoo! Thanks, man!

 

[V0latyle]

Just for grins, I extracted boot.img from the Android 12 OS Dec 5, 2021 release, which is the factory image I have been using, rebooted into the bootloader and fastboot flash boot boot.img to see if flashing was somehow corrupting the boot.img. Rebooted into system and it is rock solid.

So patching the December update with Magisk was stable? I'm not sure I see the problem. If you're able to root on the latest update and are stable, why would you want anything else?

The same problem of bootlooping after flashing magisk-patched image occurred with the Nov 2021 Android 12 factory image.

Again, why would you want to go back to November? Just use the latest release.

Then I flashed the magisk-patched boot image. Rebooted into system. The phone was stable for several minutes.
I then rebooted the phone. And the bootlooping started up again. Why does rebooting triggered the bootloop instability?

It shouldn't. As I mentioned previously, you seem to be having a unique issue. Since you mention this problem happening on two devices, you need to make sure you aren't confusing the software between the two of them. The 5a boot image won't work on the 4a and vice versa.

This is what I would do in your shoes:

1. Download the December factory image. Rename it so that you know what device it is for - i.e., "Pixel 5A Dec 2021.zip"
2. Reboot to bootloader, connect your phone via USB, and go to Android Flash Tool
3. Install the same factory update you downloaded. Make sure the build number matches. Check the "Wipe Data" and "Force Flash All Partitions" boxes.
4. When flashing is complete, set up your phone, and install Magisk 23016
5. Unzip the December factory image, then unzip the "image-device-buildnumber.zip" inside it. Copy boot.img from this zip to your device.
6. Patch boot.img in Magisk. Before you copy it back to your computer, delete ALL previously patched boot images. Make sure you rename the patched boot images so you know what device they are for, i.e., "Magisk 23016 5a.img"
7. Reboot your device to bootloader, and flash the patched boot image. MAKE SURE you are using the boot image for that specific device.

Again, I can't stress it enough - if you're doing this on more than one device, make sure you are segregating the files and folders so you don't accidentally flash the 5a firmware or boot image on the 4a and vice versa.

Also, make sure you are using Command Prompt, not PowerShell.

 

[goodjuju]

A stupid question - No need to unlock bootloader before rooting using this method?

 

[CarinaPDX]

Thanks for your work. I had issues of undetermined origin with 11, and had been delaying upgrading to 12, so as a result of the problems I wiped the 5a and did a Flash Tool install of the December factory image and then rooted with Magisk Canary; it worked well.

Today I tried 4 times to download and install the January OTA Security release, and each time it fails to finish the install after downloading. The instructions in post #1 say to take the OTA but don't mention any required prior steps. Could it be that I have to uninstall Magisk first? Or something else? Thanks for any help.

 

[V0latyle]

A stupid question - No need to unlock bootloader before rooting using this method?

Did you read the OP? Rooting is not possible without an unlocked bootloader.

Thanks for your work. I had issues of undetermined origin with 11, and had been delaying upgrading to 12, so as a result of the problems I wiped the 5a and did a Flash Tool install of the December factory image and then rooted with Magisk Canary; it worked well.

Today I tried 4 times to download and install the January OTA Security release, and each time it fails to finish the install after downloading. The instructions in post #1 say to take the OTA but don't mention any required prior steps. Could it be that I have to uninstall Magisk first? Or something else? Thanks for any help.

Nothing else should be required. I personally don't update via OTA; I use the factory image. It's normal for the OTA to fail on a rooted device, although sometimes retrying it will succeed.

Uninstalling Magisk should not be necessary. I just updated my 5 and wife's 5a without changing anything - just updated using factory image, flashed patched boot image, and done.

For those who are wondering, this is how I updated my wife's 5a (and my Pixel 5):

1. Download and extract the factory image
2. Extract boot.img from the factory update image
3. Copied boot.img to device, patched in Magisk, copied patched boot image back to update folder
4. Reboot device to bootloader
5. Apply update:

   fastboot update device-image-buildnumber.zip

6. Let device boot and finish update; reboot to bootloader
7. Boot patched image:

   fastboot boot magisk_patched-23016_xxxxx.img

8. Open Magisk, tap Install, Direct Install, then reboot.
9. Done.

You can potentially save a couple steps by using --skip-reboot when applying the update, then simply rebooting to bootloader and flashing the patched boot image.

 

[peikojose]

Did you read the OP? Rooting is not possible without an unlocked bootloader. Nothing else should be required. I personally don't update via OTA; I use the factory image. It's normal for the OTA to fail on a rooted device, although sometimes retrying it will succeed. Uninstalling Magisk should not be necessary. I just updated my 5 and wife's 5a without changing anything - just updated using factory image, flashed patched boot image, and done. For those who are wondering, this is how I updated my wife's 5a (and my Pixel 5):

1. Download and extract the factory image
2. Extract boot.img from the factory update image
3. Copied boot.img to device, patched in Magisk, copied patched boot image back to update folder
4. Reboot device to bootloader
5. Apply update:

   fastboot update device-image-buildnumber.zip

6. Let device boot and finish update; reboot to bootloader
7. Boot patched image:

   fastboot boot magisk_patched-23016_xxxxx.img

8. Open Magisk, tap Install, Direct Install, then reboot.
9. Done.

You can potentially save a couple steps by using --skip-reboot when applying the update, then simply rebooting to bootloader and flashing the patched boot image.

Doing that you need to flash the new bootloader and radio, right? I don't see you did that.

 

[CarinaPDX]

OK, thanks for that. I would rather get the OTA working as that is a lot smaller than the 2GB+ factory image to download. If I select Uninstall in Magisk and then restore images would that end up wiping or encrypting my data?

 

[CarinaPDX]

Doing that you need to flash the new bootloader and radio, right? I don't see you did that.

A full factory image has all images included. It is optional to install all partitions or just those that need updating. The whole point is that you end up with a complete OEM firmware with all partitions at a known good release. In the past, and possibly in the future, OTAs (i.e. partial updates) have on occasion not resulted in everything working right - requiring a factory image to fix. The advantage of OTAs is that they try to migrate data if there is a change of format for certain config files (especially between full releases such as 11 to 12), but this is also a potential failure point.

 

[peikojose]

A full factory image has all images included. It is optional to install all partitions or just those that need updating. The whole point is that you end up with a complete OEM firmware with all partitions at a known good release. In the past, and possibly in the future, OTAs (i.e. partial updates) have on occasion not resulted in everything working right - requiring a factory image to fix. The advantage of OTAs is that they try to migrate data if there is a change of format for certain config files (especially between full releases such as 11 to 12), but this is also a potential failure point.

I mean using this fastboot update device-image-buildnumber.zip

I don't think that will update radio and bootloader

 

[CarinaPDX]

I mean using this fastboot update device-image-buildnumber.zip

I don't think that will update radio and bootloader

If you flash the factory image it's shell script will work properly. An update command may not get you where you want to go. I have always used the command line tools but the install of 12 I did with the Android Flash Tool web app and it was very easy and clear. You should back up (sync) everything before proceeding of course.

 

[V0latyle]

Doing that you need to flash the new bootloader and radio, right? I don't see you did that.

The bootloader and baseband version in the January update are the same as December. Updating them is only necessary if the versions are different; the system update will fail if the bootloader and baseband versions don't match expected.

OK, thanks for that. I would rather get the OTA working as that is a lot smaller than the 2GB+ factory image to download. If I select Uninstall in Magisk and then restore images would that end up wiping or encrypting my data?

No. But, if you do not already have a Magisk 23016 patched boot image handy, you're still going to need that.

Uninstalling Magisk is not necessary to update.

I mean using this fastboot update device-image-buildnumber.zip

I don't think that will update radio and bootloader

If you flash the factory image it's shell script will work properly. An update command may not get you where you want to go. I have always used the command line tools but the install of 12 I did with the Android Flash Tool web app and it was very easy and clear. You should back up (sync) everything before proceeding of course.

I don't use the shell script - I manually compared the bootloader and baseband versions, and simply applied the system update. There is no need to reflash bootloader and baseband if they haven't been updated.

 

[goodjuju]

Thanks VOlatyle for the unlocked bootloader clarification. My bad. Missed the very firt line when read the instructions.

 

[nijel8]

Just in case sharing a tip for a situation I have encountered multiple times while building and testing TWRP boot.img,
This will happen if you try to boot any broken(corrupted) unbootable boot.img.
Fastboot sends the image to device and bootloader reports with unsupported. You reboot and phone goes straight to recovery with 2 options - try again or wipe data. You can't boot to Android keeping data any more despite the fact that you didn't flash anything and boot_a/b partitions are still good. In that case the only way out is to do "fastboot boot <known good boot.img>" and then do normal reboot with no lost of data.
Hope this never happens, but now you know if it does...